Synthesis and characterization of biphenyl liquid crystal based on natural molecules and 2(5H)-furanone moiety

Using 4′-hexyloxybiphenyl-4-ol and N-(5-alkoxy-3-bromo-2(5H)-furanonyl) amino acids as reactants, a series of novel biphenyl liquid crystal compounds containing natural molecule moieties, such as menthol, borneol, and amino acids, were synthesized via esterification. The structures of all novel compounds were confirmed by FTIR, ¹H NMR, ¹³C NMR, MS, and elemental analysis, and the liquid crystal properties of target compounds were characterized with DSC, XRD, and POM. The introduction of hexyloxy made the biphenyl esters have a potential to appear in mesomorphic phase and have a higher Tm, and bornyl moiety was more beneficial for the liquid crystal performance than a menthyl unit. Most compounds were mesomorphic phase liquid crystal molecules, and POM and XRD showed that they existed in smectic phase. These researches provide a theoretical basis for the synthesis of biphenyl ester liquid crystal materials via the utilization of 2(5H)-furanone derivates and natural molecules.